The only difference between elements and compounds consists in the supposed impossibility of proving the so-called elements to be compounds.
The McCarthy period came along. . . and many of the other scientists who had been working on these same lines gave up. Probably saying "Why should I sacrifice myself? I am a scientist, I am supposed to be working on scientific things, so I don't need to put myself at risk by talking about these possibilities. " And I have said that perhaps I'm just stubborn. . . I have said "I don't like anybody to tell me what to do or to think, except Mrs. Pauling. "